POST Multipart Form Data using Retrofit 2.0 includ

Question

I am trying to do a HTTP POST to server using Retrofit 2.0

        MediaType MEDIA_TYPE_TEXT = MediaType.parse("text/plain");
        MediaType MEDIA_TYPE_IMAGE = MediaType.parse("image/*");

        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        imageBitmap.compress(Bitmap.CompressFormat.JPEG, 90, byteArrayOutputStream);
        profilePictureByte = byteArrayOutputStream.toByteArray();

    Call<APIResults> call = ServiceAPI.updateProfile(
                RequestBody.create(MEDIA_TYPE_TEXT, emailString),
                RequestBody.create(MEDIA_TYPE_IMAGE, profilePictureByte));

    call.enqueue();

The server returns an error saying the file is not valid.

This is weird because I have tried to upload the same file with the same format on iOS(using other library), but it uploads successfully.

I am wondering what is the proper way to upload an image using Retrofit 2.0?

Should I save it to disk first before uploading?

Thank you!

P.S.: I have used retrofit for other Multipart request that does not include image and they completed successfully. The problem is when I am trying to include a byte to the body.

Answer 1

I am highlighting the solution in both 1.9 and 2.0 since it is useful for some

In 1.9, I think the better solution is to save the file to disk and use it as Typed file like:

RetroFit 1.9

(I don't know about your server-side implementation) have an API interface method similar to this

@POST("/en/Api/Results/UploadFile")
void UploadFile(@Part("file")TypedFile file,@Part("folder")String folder,Callback<Response> callback);

And use it like

TypedFile file = new TypedFile("multipart/form-data", new File(path));

For RetroFit 2 Use the following method

RetroFit 2.0 ( This was a workaround for an issue in RetroFit 2 which is fixed now, for the correct method refer jimmy0251's answer)

API Interface:

public interface ApiInterface {
    @Multipart
    @POST("/api/Accounts/editaccount")
    Call<User> editUser (@Header("Authorization") String authorization, @Part("file\"; filename=\"pp.png\" ") RequestBody file , @Part("FirstName") RequestBody fname, @Part("Id") RequestBody id);
}

Use it like:

File file = new File(imageUri.getPath());
RequestBody fbody = RequestBody.create(MediaType.parse("image/*"), file);
RequestBody name = RequestBody.create(MediaType.parse("text/plain"), firstNameField.getText().toString());
RequestBody id = RequestBody.create(MediaType.parse("text/plain"), AZUtils.getUserId(this));
Call<User> call = client.editUser(AZUtils.getToken(this), fbody, name, id);
call.enqueue(new Callback<User>() {
    @Override
    public void onResponse(retrofit.Response<User> response, Retrofit retrofit) {
        AZUtils.printObject(response.body());
    }

    @Override
    public void onFailure(Throwable t) {
        t.printStackTrace();
    }
});